The invention relates to a differential drive having a controllable braking device which is controlled by a differential-speed-dependent actuating device.
A differential drive with a locking device in the form of a multi-plate coupling which is controlled by a hydraulic actuating device is known from DE 38 13 304 A1. The hydraulic device is positioned outside the differential carrier, with an axially movable annular piston acting, by means of an axial pressure bearing, on a pressure ring rotating together with the differential carrier. From said pressure ring the piston force is transmitted to the multi-plate coupling by means of push rods or pressure elements. The hydraulic device is supplied by a pump positioned outside the drive housing. The axle shaft portions positioned inside the drive housing are of different length and design.
U.S. Pat. No. 4,644,823 describes a differential drive of a similar type. In this case, too, a hydraulic actuating device with an annular piston non-rotatably arranged in the drive housing is located outside the differential carrier. The annular piston loads an axially movable pressure bearing which, by means of a plate spring, acts on a pressure ring rotating in the differential carrier. The pressure ring, by means of push rods, transmits the piston force of the hydraulic device to a friction plate unit. In this case, too, the hydraulic pressure is generated by a pump outside the drive housing. The axle shaft journal parts positioned inside the differential housing and differential carrier respectively again are of different length.
It is the object of the present invention to provide a differential drive with a controllable locking device and a differential-speed-dependent actuating device which is of simple design and permits the use of identical axle shaft journals inside the differential housing.